


lacking

by aluinihi



Category: Durarara!!
Genre: Alpha Heiwajima Shizuo, Alpha/Beta/Omega Dynamics, M/M, Omega Verse, Sigma Orihara Izaya, but with a twist: the addition of Sigma, i WILL fanfic-size it this is the hill i choose to die on, thank you 4chan or reddit for coming up with the concept of Sigma male, this is like basically worldbuilding and Shizuo being very homosexual
Language: English
Status: Completed
Published: 2021-02-18
Updated: 2021-02-18
Packaged: 2021-03-14 00:40:13
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,466
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29534874
Author URL: https://archiveofourown.org/users/aluinihi/pseuds/aluinihi
Summary: Izaya Orihara had no scent; just a smile. Cunning, knife-sharp lips twisted upwards.
Relationships: Heiwajima Shizuo/Orihara Izaya
Comments: 16
Kudos: 92





	lacking

**Author's Note:**

> Hey! This fic exists thanks to a [long discussion](https://twitter.com/aluinihi/status/1356189466201907202?s=20) I had with my bleached blond, [kani](https://twitter.com/kanikrat), about how the concept of Sigma Male could fit in omegaverse society. I love him so much for indulging my weird sociological bullshit.
> 
> If are you are ~~normal~~ blissfully unaware of the hilarity that is a Sigma Male, I will kindly provide you with a [link](https://theadultman.com/love-and-lust/sigma-male/) so you can knock yourself out.
> 
> This is rather short and I can't say I'm satisfied, but I hope you have a nice reading time!

Izaya Orihara had no scent. Nothing. Not a whiff of it. 

Shizuo was taken aback the moment they met — he heard the sound of clapping, saw crimson eyes matching a red shirt and pitch-black hair, but he couldn't smell anything. He couldn't sense anything. The only feeling that boy inspired was a strange perception that there was something _lacking_ about him. Shizuo could recall the growl forming in the depths of his own chest, the mind-wracking wave of rage tangling around his heart like a vine, and then jumping into a fight that would seemingly have no end. Izaya Orihara had no scent; just a smile. Cunning, knife-sharp lips twisted upwards. He dodged Shizuo's attacks and stood unfazed by the intimidating effect Shizuo's anger brought out in every single person he had met in his life.

Being an alpha implied heightened senses, and being Shizuo Heiwajima implied taking that to a whole new level. He could smell a beta — the soft, monochromatic buzz they exhaled — from across the room. Omegas or alphas — depending on the scent, from across the block. Shinra had once theorized that the range of pheromones Shizuo can perceive could be the cause of his temperamental outbursts, as if he was living in a constant state of emotional overload, or something like that. Shizuo didn't really pay attention, much less understand. Though he did get that Izaya Orihara was not alpha, nor beta, and much less an omega.

_Sigma_ , Shinra had said. _He can't release or be affected by pheromones_.

That alone had sent Shizuo in another surge of anger.

And after that, he went back home and asked his mother about it.

She frowned at him. "Sigma? Do you know someone like that?" Then, at Shizuo's explanation, she shook her head. "Stay away from him. That kind of person is not to be trusted."

In the beginning, Shizuo agreed with her. Not only that, but he thought it'd be easy. No scent meant he wouldn't be walking around Raijin under the constant awareness of _Izaya Orihara_ and pretending he didn't exist would be the easiest thing. It'd be the first time Shizuo wouldn't have to worry about the pheromonal shadow of a bastard who pissed him off.

But of course, Izaya Orihara had different plans.

  
  


_kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill kill_

  
  


The next morning, the asshole was hiding on the school's roof, arms splayed over the railing and the devilish smile plastered to his face.

"You sent that gang after me," Shizuo accused.

With an almost-perfectly crafted innocent expression, Izaya Orihara tilted his head to the side, exposing his neck, but the wave of pheromones Shizuo expected never came. "I have no idea what you are talking about, Shizu-chan."

Shizuo's hands closed in tight fists. "Don't call me that!"

"Ah, since you're asking so politely," said Izaya. "What would Shizu-chan prefer, then? I'm thinking of _'Beast'_." He grinned. "Or maybe _Monster_."

After that, everything became a blur of red, red, red — and black hair tousled by the wind, and the silver gleam of a knife, and the chirping tone of taunting, and crimson eyes that followed Shizuo's every movement like they could eat him alive. And no scent.

Nothing. Not a whiff of it. 

It was disturbing, distressing, disconcerting: how could someone who could not _feel_ others, who could not assess their intentions or states, be so quick on his feet and escape Shizuo's grasp like he was made of butter? How could he dodge Shizuo's strength, surpass his speed, predict his strike before even Shizuo could know himself? How could Izaya Orihara, when he was _lacking?_ How could Izaya Orihara know Shizuo Heiwajima, when Shizuo Heiwajima couldn't smell a whiff of Izaya Orihara himself?

He was always so close, Shizuo's hand reached just right next to the black middle-school jacket, and Izaya slipped away by the width of a hair.

And then he laughed, tilting his head to the side, and the sharp breath Shizuo would take as a reflex brought nothing but the scent of their surroundings.

  
  


Over the years, Shizuo learned more about sigmas. They were rare, extremely so. Izaya had been the first one in Raijin in years. Perhaps, one of the few in the entirety of Tokyo. And just like Shizuo had noticed on the first day they met, sigmas are lacking — no pheromones, no glands, no receptors. If betas are considered to have mild, flexible scents, then sigmas have nothing to show. No pheromones meant they couldn't communicate normally, they couldn't sense you and your needs and you couldn't sense theirs, so all the books, and pamphlets, and late-night TV shows said the same: _therefore they can't be trusted_.

"I'm always alone no matter what I do," he groused to Celty, after one of his and Izaya's fights. "I guess Izaya is the same as me. That bastard probably doesn't have anyone he can call a friend."

Must be a lonesome existence, that of a sigma. If Shizuo, with his heightened senses and all, had such a hard time with people, he couldn't imagine what it would be like. To not have the confirmation that he wasn't unwanted — to not have the soft sweetness of Celty's scent, in that specific brand that spoke of _companionship_.

But yeah, that flea did not deserve an ounce of his sympathy.

_He is nothing like you_ , Celty's PDA said. 

Shizuo nodded, with an odd hesitation almost weighting his head immobile.

  
  


One day, Shizuo had his nose buried in Izaya's neck, right where the glands should be, and Izaya still had no scent. 

He smelled of skin, sweat, fancy soap, and shampoo. Coffee. The city's traffic. But all of those were neutral, they were supposed to be background noise to the idiosyncratic experience that Izaya Orihara should be but there was nothing. Not a whiff of it.

"Stop slobbering all over my neck," Izaya snapped. "If you bite me, I'll stab your eyeball out of the socket. But thinking better, with your monster healing, you might as well grow a new one in—"

So Shizuo moved back to his lips. To shut him up, of course.

Shizuo wasn't one to sleep around — or better yet, with his particular strength, he couldn't be one to sleep around — but he had tried before. Two omegas and a beta. With the first two, he had felt intoxicated, out of control, it was like losing his temper except that it was _good actually_ , and both smelled like strawberry cake and sweet vanilla, mouth-watering and mind-blowing. The second was an unlucky drunk night, red-dyed hair and a loud, obnoxious laugh, and rain and saltwater and whatever nostalgia he could get from Raijin's library. They all had scents, strong ones, and Shizuo knew what to do simply by breathing in and following his instincts.

But Izaya — just like everything about him, this was also difficult. When Shizuo breathed in, he was left on edge. The oddity of the lack of pheromones struck him over and over, as it did every time they met, as if Shizuo could never be truly prepared for the lack of instinctual balance, of communication, of that irrational connection he had no idea he needed until he met someone who couldn't create it.

To guide himself, Shizuo had to pay attention to other signs. The hitch of Izaya's breath, the twitch of his hips and thighs, the gasps, the whimpers, the moans. The bossing around — _Shizu-chan touch here, right there, yes, faster, harder, don't bite don't bite_ — the way Izaya clawed at his arms and back and chest and did exactly what he told Shizuo not to and _bit down_ , right on Shizuo's neck, right where it mattered, where it _would_ matter were Izaya anyone but himself. But all they got from the bite was blood, the smell bitter and heavy, sending sparks of heat down Shizuo's spine. 

Shizuo growled and Izaya let him. Let him. His body bending to Shizuo without the need for words. As if Izaya could sense what Shizuo wanted, as if he could feel it, and accommodate it like he was made for it.

  
  


In the aftermath, when they laid down on Izaya's expensive sheets, Shizuo curled an arm around him to pull him close. This time, Izaya didn't slip away, no; he hid his face in Shizuo's neck, nosed the bite he left there, and breathed in deep.

Shizuo's hold tightened.

**Author's Note:**

> I hope this wasn't bad!
> 
> Btw, I take prompt requests on [tumblr](https://aluinihi.tumblr.com) and [twitter](https://twitter.com/aluinihi), so hit me up! (preferably with a vending machine)


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